SPES (Single Particle Extinction and Scattering) takes advantage of a single particle measuring approach. In this way, it is possible to precisely and quantitatively discriminate the presence of populations with different size as present in the sample (see figure) while avoiding artefacts due to invention algorithms, as required in traditional particle sizing methods, such as Dynamic Light Scattering (DLS), Static Light Scattering (SLS) and MultiAngle Light Scattering (MALS). High accuracy and resolution on the particle size distribution are possible also for heterogeneous samples in complex biological fluids, where the presence of solid content complicates, if not prevents, any characterization measurement with a traditional instrument.
(in figure) Experimental particle size distributions of a mix of polystyrene standard samples. The histogram reports the experimental data, the red line draws the experimental cumulant curve, the blue triangles are the expected values from standards datasheets.